With the end of the Great Hyperspace War, the Republic and the Jedi began to purge the remnants of the Sith Empire‒obliterating its power centers, destroying its dark teachings and leaving its people without a clear leader. The Supreme Chancellor and his allies argued that this was not a battle against the Empire's citizenry, but a necessary step to free the Sith from corruption.
The survivors among the Sith‒and they were few, as famine, disease and infighting claimed those who did not continue to face down the Republic‒saw it as a deathblow to their culture. But a savior arose: The man who would one day become Emperor of the Sith had weathered the war with a number of trusted followers. No record of the Sith Emperor's original identity has survived, but he was quickly accepted as the leader of the almost-shattered Sith Empire.
Although the Republic had temporarily retreated from the Horuset system, the Sith Emperor knew that Korriban would not be safe for long. While the few survivors emerged from their shelters in the deserts and shattered tombs, the Sith Emperor began to devise a plan, centuries in the execution, that would ensure the survival of the Sith and the eventual annihilation of the Republic.